The present disclosure herein relates to a substrate inspecting method, and more particularly, to a substrate inspecting method capable of inspecting a pad area of a substrate.
In general, a liquid crystal display device includes a first substrate where a plurality of pixels are defined, a second substrate facing the first substrate where color filters corresponding to the plurality of pixels are arranged, and a liquid crystal layer between the first substrate and the second substrate. The first substrate may be defined as a thin film transistor substrate or a display substrate. Additionally, the second substrate may be defined as a color filter substrate or a facing substrate.
The thin film transistor substrate includes a plurality of gate lines, a plurality of data lines insulated from and intersecting the gate lines, and a plurality of thin film transistors connected to the gate lines and the data lines in an intersection area of the gate lines and the data lines. The pixels receive pixel voltages through each of the corresponding thin film transistors. Due to the pixel voltages, the arrangement of liquid crystals in a liquid crystal layer changes. According to the changed arrangement of the liquid crystals, light transmittance is adjusted to display an image.
While display panels are manufactured, various inspections are performed to detect defective panels. For example, in order to inspect the pixels of the first substrate, an open/short (OS) test, a visual inspection (VI), and an auto optical inspection (AOI) may be used.